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superclass: object% | ||
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Whenever the user changes the value of a slider, its callback procedure is invoked. A callback procedure is provided as an initialization argument when each slider is created.
constructor
(new slider% [label label] [min-value min-value] [max-value max-value] [parent parent] [ [callback callback] [init-value init-value] [style style] [font font] [enabled enabled] [vert-margin vert-margin] [horiz-margin horiz-margin] [min-width min-width] [min-height min-height] [stretchable-width stretchable-width] [stretchable-height stretchable-height]]) → (is-a?/c slider%) label : (or/c label-string? #f) min-value : (integer-in -10000 10000) max-value : (integer-in -10000 10000)
parent :
(or/c (is-a?/c frame%) (is-a?/c dialog%) (is-a?/c panel%) (is-a?/c pane%))
callback : ((is-a?/c slider%) (is-a?/c control-event%) . -> . any) = (lambda (b e) (void)) init-value : (integer-in -10000 10000) = min-value
style :
(listof (or/c 'horizontal 'vertical 'plain 'vertical-label 'horizontal-label 'deleted)) = '(horizontal) font : (is-a?/c font%) = normal-control-font enabled : any/c = #t vert-margin : (integer-in 0 1000) = 2 horiz-margin : (integer-in 0 1000) = 2 min-width : (integer-in 0 10000) = graphical-minimum-width min-height : (integer-in 0 10000) = graphical-minimum-height stretchable-width : any/c = (memq 'horizontal style) stretchable-height : any/c = (memq 'vertical style)
If & occurs in label, it is specially parsed as for button%.
The min-value and max-value arguments specify the range of the slider, inclusive. The init-value argument optionally specifies the slider’s initial value. If the sequence [min-value, initial-value, maximum-value] is not increasing, an exn:fail:contract exception is raised.
The callback procedure is called (with the event type 'slider) when the user changes the slider’s value.
The style argument must include either 'vertical for a vertical slider, or 'horizontal for a horizontal slider. If style includes 'plain, the slider does not display numbers for its range and current value to the user. If style includes 'vertical-label, then the slider is created with a label above the control; if style does not include 'vertical-label (and optionally includes 'horizontal-label), then the label is created to the left of the slider. If style includes 'deleted, then the slider is created as hidden, and it does not affect its parent’s geometry; the slider can be made active later by calling parent’s add-child method.
The font argument determines the font for the control. For information about the enabled argument, see window<%>. For information about the horiz-margin and vert-margin arguments, see subarea<%>. For information about the min-width, min-height, stretchable-width, and stretchable-height arguments, see area<%>.
method
(send a-slider get-value) → (integer-in -10000 10000)
method
value : (integer-in -10000 10000)